1 /* $NetBSD: rec_open.c,v 1.14 2005/06/01 05:39:17 lukem Exp $ */ 2 3 /*- 4 * Copyright (c) 1990, 1993, 1994 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Mike Olson. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 #if defined(LIBC_SCCS) && !defined(lint) 37 #if 0 38 static char sccsid[] = "@(#)rec_open.c 8.10 (Berkeley) 9/1/94"; 39 #else 40 __RCSID("$NetBSD: rec_open.c,v 1.14 2005/06/01 05:39:17 lukem Exp $"); 41 #endif 42 #endif /* LIBC_SCCS and not lint */ 43 44 #include "namespace.h" 45 #include <sys/types.h> 46 #include <sys/mman.h> 47 #include <sys/stat.h> 48 49 #include <errno.h> 50 #include <fcntl.h> 51 #include <limits.h> 52 #include <stddef.h> 53 #include <stdio.h> 54 #include <unistd.h> 55 56 #include <db.h> 57 #include "recno.h" 58 59 DB * 60 __rec_open(fname, flags, mode, openinfo, dflags) 61 const char *fname; 62 int flags; 63 mode_t mode; 64 const RECNOINFO *openinfo; 65 int dflags; 66 { 67 BTREE *t; 68 BTREEINFO btopeninfo; 69 DB *dbp; 70 PAGE *h; 71 struct stat sb; 72 int rfd = -1; /* pacify gcc */ 73 int sverrno; 74 75 dbp = NULL; 76 /* Open the user's file -- if this fails, we're done. */ 77 if (fname != NULL) { 78 if ((rfd = open(fname, flags, mode)) == -1) 79 return (NULL); 80 if (fcntl(rfd, F_SETFD, FD_CLOEXEC) == -1) 81 goto err; 82 } 83 84 /* Create a btree in memory (backed by disk). */ 85 if (openinfo) { 86 if (openinfo->flags & ~(R_FIXEDLEN | R_NOKEY | R_SNAPSHOT)) 87 goto einval; 88 btopeninfo.flags = 0; 89 btopeninfo.cachesize = openinfo->cachesize; 90 btopeninfo.maxkeypage = 0; 91 btopeninfo.minkeypage = 0; 92 btopeninfo.psize = openinfo->psize; 93 btopeninfo.compare = NULL; 94 btopeninfo.prefix = NULL; 95 btopeninfo.lorder = openinfo->lorder; 96 dbp = __bt_open(openinfo->bfname, 97 O_RDWR, S_IRUSR | S_IWUSR, &btopeninfo, dflags); 98 } else 99 dbp = __bt_open(NULL, O_RDWR, S_IRUSR | S_IWUSR, NULL, dflags); 100 if (dbp == NULL) 101 goto err; 102 103 /* 104 * Some fields in the tree structure are recno specific. Fill them 105 * in and make the btree structure look like a recno structure. We 106 * don't change the bt_ovflsize value, it's close enough and slightly 107 * bigger. 108 */ 109 t = dbp->internal; 110 if (openinfo) { 111 if (openinfo->flags & R_FIXEDLEN) { 112 F_SET(t, R_FIXLEN); 113 t->bt_reclen = openinfo->reclen; 114 if (t->bt_reclen == 0) 115 goto einval; 116 } 117 t->bt_bval = openinfo->bval; 118 } else 119 t->bt_bval = '\n'; 120 121 F_SET(t, R_RECNO); 122 if (fname == NULL) 123 F_SET(t, R_EOF | R_INMEM); 124 else 125 t->bt_rfd = rfd; 126 127 if (fname != NULL) { 128 /* 129 * In 4.4BSD, stat(2) returns true for ISSOCK on pipes. 130 * Unfortunately, that's not portable, so we use lseek 131 * and check the errno values. 132 */ 133 errno = 0; 134 if (lseek(rfd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) { 135 switch (flags & O_ACCMODE) { 136 case O_RDONLY: 137 F_SET(t, R_RDONLY); 138 break; 139 default: 140 goto einval; 141 } 142 slow: if ((t->bt_rfp = fdopen(rfd, "r")) == NULL) 143 goto err; 144 F_SET(t, R_CLOSEFP); 145 t->bt_irec = 146 F_ISSET(t, R_FIXLEN) ? __rec_fpipe : __rec_vpipe; 147 } else { 148 switch (flags & O_ACCMODE) { 149 case O_RDONLY: 150 F_SET(t, R_RDONLY); 151 break; 152 case O_RDWR: 153 break; 154 default: 155 goto einval; 156 } 157 158 if (fstat(rfd, &sb)) 159 goto err; 160 /* 161 * Kluge -- we'd like to test to see if the file is too 162 * big to mmap. Since, we don't know what size or type 163 * off_t's or size_t's are, what the largest unsigned 164 * integral type is, or what random insanity the local 165 * C compiler will perpetrate, doing the comparison in 166 * a portable way is flatly impossible. Hope that mmap 167 * fails if the file is too large. 168 */ 169 if (sb.st_size == 0) 170 F_SET(t, R_EOF); 171 else { 172 #ifdef MMAP_NOT_AVAILABLE 173 /* 174 * XXX 175 * Mmap doesn't work correctly on many current 176 * systems. In particular, it can fail subtly, 177 * with cache coherency problems. Don't use it 178 * for now. 179 */ 180 t->bt_msize = sb.st_size; 181 if ((t->bt_smap = mmap(NULL, t->bt_msize, 182 PROT_READ, MAP_FILE | MAP_PRIVATE, rfd, 183 (off_t)0)) == (caddr_t)-1) 184 goto slow; 185 t->bt_cmap = t->bt_smap; 186 t->bt_emap = t->bt_smap + sb.st_size; 187 t->bt_irec = F_ISSET(t, R_FIXLEN) ? 188 __rec_fmap : __rec_vmap; 189 F_SET(t, R_MEMMAPPED); 190 #else 191 goto slow; 192 #endif 193 } 194 } 195 } 196 197 /* Use the recno routines. */ 198 dbp->close = __rec_close; 199 dbp->del = __rec_delete; 200 dbp->fd = __rec_fd; 201 dbp->get = __rec_get; 202 dbp->put = __rec_put; 203 dbp->seq = __rec_seq; 204 dbp->sync = __rec_sync; 205 206 /* If the root page was created, reset the flags. */ 207 if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL) 208 goto err; 209 if ((h->flags & P_TYPE) == P_BLEAF) { 210 F_CLR(h, P_TYPE); 211 F_SET(h, P_RLEAF); 212 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 213 } else 214 mpool_put(t->bt_mp, h, 0); 215 216 if (openinfo && openinfo->flags & R_SNAPSHOT && 217 !F_ISSET(t, R_EOF | R_INMEM) && 218 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR) 219 goto err; 220 return (dbp); 221 222 einval: errno = EINVAL; 223 err: sverrno = errno; 224 if (dbp != NULL) 225 (void)__bt_close(dbp); 226 if (fname != NULL) 227 (void)close(rfd); 228 errno = sverrno; 229 return (NULL); 230 } 231 232 int 233 __rec_fd(dbp) 234 const DB *dbp; 235 { 236 BTREE *t; 237 238 t = dbp->internal; 239 240 /* Toss any page pinned across calls. */ 241 if (t->bt_pinned != NULL) { 242 mpool_put(t->bt_mp, t->bt_pinned, 0); 243 t->bt_pinned = NULL; 244 } 245 246 /* In-memory database can't have a file descriptor. */ 247 if (F_ISSET(t, R_INMEM)) { 248 errno = ENOENT; 249 return (-1); 250 } 251 return (t->bt_rfd); 252 } 253